A binary signal with random noise-like properties. It is generated by mathematical algorithm or "code", and consists of repeated pattern of 1's and 0's. This binary code can be modulated on the GPS carrier waves using Binary Shift-Key (BSK) modulation. The C/A-Code and the P-Code are examples of PRN codes. Each satellite transmits a unique C/A-Code and P-Code sequence (on the same L1 and L2 frequencies), and hence a satellite may be identified according to its "PRN number", e.g. PRN2 or PRN14 are particular GPS satellites.